Stephanofilaria boomkeri n. sp., as a cause of severe skin disease in pigs in Zaire.

A new Stephanofilaria, S. boomkeri n. sp., is described as the cause of skin lesions in pigs in Zaire. It is the first species described in suids. The reservoirs might be wild African suids. The six valid species of the genus Stephanofilaria form two main groups. In one group, female worms lay sheathed microfilariae; members of this group are exclusively African and are represented by the parasite of rhinoceros, S. dinnicki, and hippopotamus, S. thelazioides. Their morphology is primitive. In the other group, female worms lay particular "eggs" which contain microfilariae S. boomkeri belongs to this group, and is regarded by its cephalic structures as the most primitive representative in this group. The other species S. dedoesi and S. zaheeri, parasitize cattle in the Asiatic region. In the holarctic region, another parasite of cattle, S., stilesi, seems to be a highly specialized member of this second group. In this species as in S. boomkeri, the envelope of the "egg" is very thick and complex, probably from peculiar adaptations in order to withstand the dessication of the microfilaria. The genus Stephanofilaria seems to have an Aethiopian origin, as in this region the species are more primitive and more varied as are also their hosts.